[rt7085]

In 2022, I replaced my failed water pump on my 2008 E91 328xi wagon. The pump was an all aluminum Pierburg version. I also replaced ALL coolant system hoses (except the ones that go to the cabin heater core) and the thermostat. My 'touch a hose you replace a hose' rule on a car of this age.

A few weeks ago I started developing a new coolant leak. After a considerable amount spent with mirrors, borescopes and removing the reinforcement plate to get a good look I have observed 2 leaks in fact.

I *think* the water pump is leaking the blue coolant from the seam between the impeller housing and the e-motor section. See the picture below. Is this a common failure of these pumps? Note: It leaks when I pressurize the coolant system to approx. 20 psi. It is a fast dripping, about once every two seconds. It stops when the pressure is relieved. I think the seal has let go. And I made sure none of the hose connections is leaking by cleaning and pressurizing the system.



The second leak is from the AC compressor. I think it is leaking the refrigerant oil. It appears more green. See the picture below. It is very slowly dropping. Is this also a common failure for these compressors?



Thank you for your insights!